/*
 _____ _             _              _           _
|_   _| |__   ___   / \   _ __  ___| |__  _   _| |
  | | | '_ \ / _ \ / _ \ | '_ \/ __| '_ \| | | | |
  | | | | | |  __// ___ \| | | \__ \ | | | |_| | |
  |_| |_| |_|\___/_/   \_\_| |_|___/_| |_|\__,_|_|

*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll          int
#define pb          push_back
#define ppb         pop_back
#define	endl		'\n'
#define mii         map<ll,ll>
#define msi         map<string,ll>
#define mis         map<ll, string>
#define rep(i,a,b)    for(ll i=a;i<b;i++)
#define repr(i,a,b) for(ll i=b-1;i>=a;i--)
#define trav(a, x) 	for(auto& a : x)
#define pii         pair<ll,ll>
#define vi          vector<ll>
#define vii         vector<pair<ll, ll>>
#define vs          vector<string>
#define all(a)      (a).begin(),(a).end()
#define F           first
#define S           second
#define sz(x)       (ll)x.size()
#define hell        1000000007
#define lbnd        lower_bound
#define ubnd        upper_bound
#define max(a,b)	(a>b?a:b)
#define min(a,b)	(a<b?a:b)

/*	For Debugging	*/
#define DEBUG 		cerr<<"\n>>>I'm Here<<<\n"<<endl;
#define display(x) trav(a,x) cout<<a<<" ";cout<<endl;
#define what_is(x)  cerr << #x << " is " << x << endl;

std::mt19937_64 rng(std::chrono::steady_clock::now().time_since_epoch().count());
#define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag,tree_order_statistics_node_update>
#define TIME        cerr << "\nTime elapsed: " << setprecision(5) <<1000.0 * clock() / CLOCKS_PER_SEC << "ms\n";
#define DECIMAL(n)  cout << fixed ; cout << setprecision(n);
#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace __gnu_pbds;
using namespace std;
#define PI 3.141592653589793
#define N  100005
vi a[N];
ll par[N],maxHeight[N],maxPath[N],ans[N];


void fun(ll node,ll height,ll path) {
	vii tmp1,tmp2;

	tmp1.pb({height,-1});
	tmp2.pb({path,-1});

	for(auto i : a[node]) {
		if(i != par[node]) {
			tmp1.pb({maxHeight[i],i});
			tmp2.pb({maxPath[i],i});
		}
	}

	sort(all(tmp1));
	sort(all(tmp2));
	reverse(all(tmp1));
	reverse(all(tmp2));


	auto find_best_height = [&] (vi v) {
		set<ll> st;
		for(auto i:v) {
			st.insert(i);
		}

		trav(j,tmp1) {
			if(st.find(j.S)==st.end()) {
				return j.F;
			}
		}
		return 0;
	};

	auto find_best_two_height = [&] (ll i) {
		if(sz(tmp1)<=2) {
			return -2;
		}
		ll sum = 0,cnt = 2;
		trav(j,tmp1) {
			if(j.S!=i) {
				sum+=j.F;
				cnt--;
				if(cnt==0) {
					return sum;
				}
			}
		}
		return -2;
	};


	auto find_best_path = [&] (vi v) {
		set<ll> st;
		for(auto i:v) {
			st.insert(i);
		}

		trav(j,tmp2) {
			if(st.find(j.S)==st.end()) {
				return j.F;
			}
		}
		return 0;
	};



	for(auto i : a[node]) {
		if(i != par[node]) {
			fun(i,find_best_height({i}), max(find_best_two_height(i) + 2, find_best_path({i})));
		}
	}

	ans[node] = 0;

	for(auto i : tmp2) {
		ans[node] = max(ans[node],i.F * (find_best_two_height(i.S) + 2) );
	}

	// for(auto i:a[node]) {
	// 	if(i!=par[node]) {
	// 		ans[node] = max(ans[node],(height + maxHeight[i] + 2) * find_best_path({i,-1}));
	// 	}
	// }

}

void precalc(ll node) {
	vi tmp;
	for(auto i : a[node]) {
		if(par[node] != i) {
			par[i] = node;
			precalc(i);
			tmp.pb(-maxHeight[i]);
			maxHeight[node] = maxHeight[i] + 1;
			maxPath[node] = max(maxPath[node],maxPath[i]);
		}
	}
	if(sz(tmp) > 1) {
		sort(all(tmp));
		maxPath[node] = max(maxPath[node],-(tmp[0]+tmp[1]));
	}
	return;
}

void solve()
{
	ll n,x,y;
	cin>>n;
	rep(i,1,n) {
		cin>>x>>y;
		a[x].pb(y);
		a[y].pb(x);
	}
	par[1] = -1;
	precalc(1);
	fun(1,0,0);
	ll pans=0;
	rep(i,1,n+1) {
		pans=max(pans,ans[i]);
	}
	cout<<pans<<endl;
	return;
}
int main()
{
	FAST
	int TESTS=1;
//	cin>>TESTS;
	rep(i,0,TESTS)
    {
        // cout<<"Case #"<<i+1<<": ";
        solve();
    }
	TIME
	return 0;
}